dft_tools/pytriqs/wrap_generator/wrap_generator.py

import sys
import re
import os
from mako.template import Template
import importlib

# the xxx_desc.py will always be called by cmake command, with the proper arguments
# analyse sys.argv right now : we need it early for the use_module
# The mako files for the wrapper and the header, and the file to write (_target)
wrapper_mako, wrapper_target, header_mako, header_target = sys.argv[1:5]
# Directories where to find the headers generated by other modules
module_path_list = sys.argv[5:]

# the correspondance c type -> py_type
c_to_py_type = {'void' : 'None', 'int' : 'int', 'long' : 'int', 'double' : "float", "std::string" : "str"}

# Translation for formatting of parsing converter.
basic_types_formatting = {'double' : 'd', 'int' : 'i'}

# Translate the name of the c++ type to the python type.
# for doc signatures.
def translate_c_type_to_py_type(t) :
    if t in c_to_py_type : return c_to_py_type[t]
    m = re.match('std::vector<(.*)>',t)
    if m: return "list[%s]"%translate_c_type_to_py_type(m.group(1))
    # numpy, etc...
    return t

class cfunction :
    """
       Representation of one overload of a C++ function or method.
    """
    def __init__(self, signature, calling_pattern = None, no_self_c = False, is_constructor = False,
             is_method = False,  is_static = False, release_GIL_and_enable_signal = False, c_name = None, doc = '') :
      """
        - signature :
             signature of the function, with types, parameter names and defaut value
             rtype( arg1 name1, arg2 name2 = default2, ....)
             it can be :
                - a string :
                     rtype (arg1 name1, arg2 name2 = default2, ....)
                - a string :
                     rtype c_name ( arg1 name1, arg2 name2 = default2, ....)
                - a dict [expert only] : rtype -> string , args -> list of tuples [ (c_type, variable_name, default_value)]
                           where rtype is the C++ type returned by the function.

        - calling_pattern :
              A string containing a piece of C++ code to call the C++ function.
              This code can use :
                - self_c  : a reference to the C++ object (except for constructor, and static method).
                - self_class : the name of the class of the C++ object (only for static method)
                - the name of the parameters.
              It should define a "result" variable :
                - unless for a constructor or if the C++ return type is void.
                - result shall be of any type from which the C++ return type is (move) constructible.
              If calling_pattern is None, a default one is synthesized by the generator,
              assuming the C++ function has exactly the signature given by the signature parameter of this function
              including the c_name in it (which is then mandatory).

        - no_self_c : boolean. do not generate self_c reference in C++ code, in some rare calling_pattern. Avoid a compiler warning.
        - is_constructor : boolean
        - is_method : boolean
        - is_static : boolean. If True, it is a static method
        - release_GIL_and_enable_signal [expert only] :
           - For long functions in pure C++.
           - If True, the GIL is released in the call of the C++ function and restored after the call.
           - It also saves the signal handler of python and restores it after the call,
             and enables the C++ triqs signal_handler.
           - This allows e.g. to intercept Ctrl-C during the long C++ function.
           - **Requirement** :
              The function wrapped must be pure C++, i.e.  no call whatsoever to the python C API, directly or indirectly.
              otherwise the behaviour is undefined.
        - doc : the doc string.
        - c_name : Internal use only.
      """
      self._calling_pattern = calling_pattern
      self.is_constructor = is_constructor
      self.no_self_c = no_self_c
      self.doc = doc
      self.is_method = is_method
      self.is_static = is_static
      if is_static : assert is_method, "is_static only works with method"
      self.release_GIL_and_enable_signal = release_GIL_and_enable_signal
      assert isinstance(signature, str) or isinstance(signature, dict), "Signature must be a string of a dict: cf doc"
      self.c_name = c_name # Not none for internal call only
      ## Analyse signature.
      self.args = []
      if isinstance(signature, str) : # it is a string, we analyse it to get the rtype, and args
        signature = re.sub('operator\(\s*\)','__operator_call',signature) # temp. replacement, to make the regex easier
        m = re.match(r"\s*(.*?)\s*\((.*)\)",signature)
        self.rtype, args = m.group(1).strip() or None, m.group(2).strip()
        # extract the c_name if present
        if self.rtype :
            spl = self.rtype.strip().rsplit(' ',1)
            if not is_constructor and len(spl)> 1 and '>' not in spl[-1] :
                self.rtype, self.c_name = spl
                if self.c_name == '__operator_call' : self.c_name = "operator()"

        def f(): # analyse the argument, be careful that , can also be in type, like A<B,C>, so we count the < >
            acc = ''
            for s in args.split(',') :
                acc += (',' if acc else '') + s.strip()
                if acc.count('<') == acc.count('>') :
                    r, acc = acc,''
                    yield r
        args = [ re.sub('=',' ',x).split() for x in f() if x] # list of (type, name, default) or (type, name)
      else :
          self.rtype = signature.pop("rtype", None)
          args = signature.pop('args',())
          self.c_name = signature.pop("c_name", '')
      for a in args: # put back the default if there is none
        # treat the case when the type is const T *, or T* (e.g. const char *).
        # Need to regroup the first pieces.
        if a[0] == 'const' : a = [' '.join(a[:2])] + list(a[2:])
        if a[1] == '*' : a = [' '.join(a[:2])] + list(a[2:])
        if len(a) == 2 : (t,n),d = a,None
        elif len(a) == 3 : t,n,d = a
        else : raise RuntimeError, "Syntax error in overload: args = %s"%args
        self.args.append([t,n,d])
      # end analyze signature
      assert self.c_name or self._calling_pattern or self.is_constructor, "You must specify a calling_pattern or the signature must contain the name of the function"
      if self.is_constructor :
        assert self.rtype == None,  "Constructor must not have a return type"
        self.is_method = False

    def _get_calling_pattern(self) :
        """Generation only: gets the calling_pattern or synthesize the default"""
        if self._calling_pattern : return self._calling_pattern
        s= "%s result = "%self.rtype if self.rtype != "void" else ""
        self_c = ""
        if self.is_method:
            self_c = "self_c." if not self.is_static else "self_class::"
        # the wrapped types are called by pointer
        return "%s %s%s(%s)"%(s,self_c, self.c_name , ",".join([ ('*' if t in module_._wrapped_types else '') + n for t,n,d in self.args]))

    def _get_signature (self):
        """Signature for the python doc"""
        rtype = translate_c_type_to_py_type(self.rtype) if self.rtype else ''
        args_rep = ", ".join(["%s %s%s"%(translate_c_type_to_py_type(t),n,' = ' + str(d) if d else '') for t,n,d in self.args])
        return "({args_rep}) -> {rtype}".format(**locals())

    def _get_c_signature (self):
        """Signature for the C++ calling errors"""
        name = self.c_name if self.c_name else "(no C++ name)"
        rtype = self.rtype if self.rtype else ''
        args_rep = ", ".join(["%s %s"%(t,n) for t,n,d in self.args])
        return "{name}({args_rep}) -> {rtype}".format(**locals())

    def __repr__(self):
        return "C++ function of signature :  %s"%(self._get_signature())

    def _parsing_format(self) :
      """Generation only: the formatting for the PyParse_xxx calls"""
      def f(t) :
          return basic_types_formatting[t] if t in basic_types_formatting else 'O&'
      l1 = [ f(t) for  t,n,d in self.args if d==None]
      l2 = [ f(t) for  t,n,d in self.args if d!=None]
      if l2 : l2.insert(0,'|') # starts the default arguments, cf python doc
      return ''.join(l1 + l2)

    def _generate_doc(self) :
        doc = "\n".join([ "   " + x.strip() for x in self.doc.split('\n')])
        return "Signature : %s\n%s"%( self._get_signature(),doc)

class pyfunction :
    """
       Representation of one python function of the extension
       It is basically :
         - a python name
         - a list of overload
         - possibly some preprocessing/postprocessing python code.
    """
    def __init__(self, name, arity = None, is_method = False, is_static = False, doc = '', python_precall = None, python_postcall = None):
      """
        - name : name given in Python
        - arity : arity of the function
        - is_method : boolean
        - is_static : boolean. Is is a static method
        - doc : the doc string.
        - overloads : a list of cfunction objects representing the various C++ overloads of the function
        - python_precall : a python function_ to be called before the call of the C++ function
                           The function must take  F(*args, **kw) and return (args, kw)
        - python_postcall : a python function_ to be called after the call of the C++ function
                           The function must take a python object, and return one...
      """
      self.py_name =name       # name given in python
      self.arity = arity
      self.is_method = is_method  # can be a method, a function...
      self.is_static = is_static  #
      self.doc = doc
      self.python_precall, self.python_postcall  = python_precall, python_postcall
      self.overloads = [] # List of all C++ overloads
      self.do_implement = True # in some cases, we do not want to implement it automatically, (special methods).
      self.is_constructor = False

    def add_overload(self, **kw) :
        self.overloads.append(cfunction(**kw))

    def _generate_doc(self) :
        s = "\n".join([self.doc, "\n"] + [f._generate_doc() for f in self.overloads])
        return repr(s)[1:-1] # remove the ' ' made by repr

class pure_pyfunction_from_module :
    """
       Representation of one python function defined in Python code in an external module.
       Will be use to make a pure python method of an object, or or a module.
       Data :
        - name : name given in Python
        - doc : the doc string.
        - module : module path to the function [pure python only]
    """
    def __init__(self, name, module) :
      """ """
      self.py_name, self.module = name, module
      try :
          m = __import__(module.rsplit('.')[-1])
          f = getattr(m,name)
          self.doc = f.__doc__ # get the doc and check the function can be loaded.
      except :
          print " I can not import the function %s from the module %s"%(name,module)
          raise

    def _generate_doc(self) :
        return self.doc

class python_function:
    """
    A python function, given as a function.
    Its code gets analysed and will be put into the C++ wrapper, to avoid import.
    """
    def __init__(self, name, f) :
        """ """
        self.name, self.f = name,f
        import inspect as ins
        self.code = "\n".join(['"%s\\n"'%line.rstrip().replace('"', '\\"') for line in ins.getsourcelines(self.f)[0]])
        self.doc = f.__doc__ # UNUSED AT THE MOMENT ??? REALLY ???

def _is_type_a_view(c_type) :
    return c_type.split('<', 1)[0].endswith("_view") # A bit basic ?

def _regular_type_if_view_else_type(c_type) :
    return "typename %s::regular_type"%c_type if _is_type_a_view(c_type) else c_type

class class_ :
    """
       Representation of a wrapped type
    """
    hidden_python_function = {} # global dict of the python function to add to the module, hidden for the user, for precompute and so on
    def __init__(self, py_type, c_type, c_type_absolute = None, hdf5 = False, arithmetic = None, serializable = None, is_printable = False, doc = '' ) :
      """
        - py_type : Name given in Python
        - c_type : C++ type to be wrapped.
        - c_type_absolute : full path of c_type, no using, no alias (need for the py_converter hpp file)
        - hdf5 : generate the hdf5 write/read function from C++ triqs hdf5 protocol and register them in the hdf_archive
        - arithmetic : determines the operations to be implemented.
            - The idea is to give an abstract description of the mathematical structure to be implemented :
              an algebra, a group, a vector space, and so on.
              The generator will then implement all necessary functions, by calling their C++ counterparts.
            - Possible values :
                 - ("abelian_group") : implements + and -
                 - ("vector_space", Scalar) : implements a vector_space, with scalar Scalar
                 - ("algebra", Scalar) : implements an algebra, with scalar Scalar
                 - ("algebra_with_unit", with_options..., Scalars...) :
                    implements an algebra, with:
                      - scalars Scalar... : the scalars
                      - with_options is (possibly empty) list of options :
                          - with_unit :  +/- of an element with a scalar (injection of the scalar with the unit)
                          - with_unary_minus  : implement unary minus
                 - "add_only" : implements only +
                 - .... more to be defined.
        - serializable : Whether and how the object is to be serialized.  Possible values are :
             - "tuple" : reduce it to a tuple of smaller objects, using the
                boost serialization compatible template in C++, and the converters of the smaller objects.
             - "via_string" : serialize via a string, made by
                triqs::serialize/triqs::deserialize
                On modern hdf5 (>1.8.9) it uses hdf5 to make the string, on older version it will use boost serialization
                (which generates a very heavy code, sometimes can x2 the code size of the wrapper, just for this function !).
        - is_printable = If true, generate the str, repr from the C++ << stream operator
        - doc : the doc string.
      """
      self.c_type = c_type
      self.c_type_absolute = c_type_absolute or c_type
      self.c_type_is_view = _is_type_a_view(c_type)
      self.implement_regular_type_converter = self.c_type_is_view # by default, it will also make the converter of the associated regular type
      if self.c_type_is_view :
          self.regular_type = 'typename ' +  self.c_type + '::regular_type'
          self.regular_type_absolute = 'typename ' +  self.c_type_absolute  + '::regular_type'
      self.py_type = py_type
      c_to_py_type[self.c_type] = self.py_type # register the name translation for the doc generation
      self.hdf5 = hdf5
      assert serializable in [None, "via_string", "tuple"]
      self.serializable = serializable
      self.is_printable = is_printable
      self.iterator = None
      self.doc = doc
      self.methods = {} #  a dict : string -> pyfunction for each method name
      self.pure_python_methods= {}
      self.constructor = None # a pyfunction  for the constructors.
      self.members= [] # a list of _member
      self.properties= [] # a list of _property

      # Init arithmetic
      # expect a tuple : "algebra", "scalar1", "scalar2", etc...
      self.number_protocol = {}
      if arithmetic :
          if not isinstance(arithmetic, tuple) : arithmetic = (arithmetic,)
          # read the with_... option and clean them for the list
          with_unary_minus = 'with_unary_minus' in arithmetic
          with_unit = 'with_unit' in arithmetic
          arithmetic = [x for x in arithmetic if not x.startswith("with_")]
          add =  arithmetic[0] in ("algebra", "abelian_group", "vector_space", "only_add")
          abelian_group = arithmetic[0] in ("algebra",  "abelian_group", "vector_space")
          vector_space = arithmetic[0] in ("algebra", "vector_space")
          algebra = arithmetic[0] in ("algebra",)

          if add :
            # add
            add = pyfunction(name ="__add__",arity = 2)
            add.add_overload (calling_pattern = "+", signature = {'args' : [(self.c_type,'x'), (self.c_type,'y')], 'rtype' :self.c_type})
            self.number_protocol['add'] = add

          if abelian_group :
            #sub
            sub = pyfunction(name ="__sub__",arity = 2)
            sub.add_overload (calling_pattern = "-", signature = {'args' :[(self.c_type,'x'), (self.c_type,'y')], 'rtype' : self.c_type})
            self.number_protocol['subtract'] = sub

          if vector_space :
            # mul
            mul = pyfunction(name ="__mul__", arity = 2)
            for scalar in arithmetic[1:] :
               mul.add_overload (calling_pattern = "*", signature = {'args' :[(self.c_type,'x'), (scalar,'y')], 'rtype' : self.c_type})
               mul.add_overload (calling_pattern = "*", signature = {'args' :[(scalar,'x'), (self.c_type,'y')], 'rtype' : self.c_type})
            self.number_protocol['multiply'] = mul
            # div
            div = pyfunction(name ="__div__", arity = 2)
            for scalar in arithmetic[1:] :
               div.add_overload (calling_pattern = "/", signature = {'args' :[(self.c_type,'x'), (scalar,'y')], 'rtype' : self.c_type})
            self.number_protocol['divide'] = div

          if algebra :
            mul.add_overload (calling_pattern = "*", signature = {'args' :[(self.c_type,'x'), (self.c_type,'y')], 'rtype' : self.c_type})

          if with_unit: # Allow + and - between scalar and operator
            assert algebra, "The with_unit option only makes sense for algebra"
            for scal in arithmetic[1:] :
                add = self.number_protocol['add']
                add.add_overload (calling_pattern = "+", signature = {'args' :[(self.c_type,'x'), (scal,'y')], 'rtype' : self.c_type})
                add.add_overload (calling_pattern = "+", signature = {'args' :[(scal,'x'), (self.c_type,'y')], 'rtype' : self.c_type})
                sub = self.number_protocol['subtract']
                sub.add_overload (calling_pattern = "-", signature = {'args' :[(self.c_type,'x'), (scal,'y')], 'rtype' : self.c_type})
                sub.add_overload (calling_pattern = "-", signature = {'args' :[(scal,'x'), (self.c_type,'y')], 'rtype' : self.c_type})

          if with_unary_minus :
                # Allow unary - on an operator
                neg = pyfunction(name = "__neg__", arity = 1)
                neg.add_overload (calling_pattern = "-", signature = {'args' :[(self.c_type,'x')], 'rtype' : self.c_type})
                self.number_protocol['negative'] = neg

    def add_constructor(self, signature, calling_pattern = None, python_precall = None, python_postcall = None, build_from_regular_type_if_view = True, doc = ''):
        """
        - signature : signature of the function, with types, parameter names and defaut value
             rtype( arg1 name1, arg2 name2 = default2, ....)
             signature can be :
                - a string of 2 possible forms (i.e. c_name can be omitted) :
                     - rtype (arg1 name1, arg2 name2 = default2, ....)
                     - rtype c_name ( arg1 name1, arg2 name2 = default2, ....)
                - a dict : rtype -> string , args -> list of tuples [ (c_type, variable_name, default_value)]
                - rtype : the C++ type returned by the function. None for constructor
             default_value is None when there is no default.
        - calling_pattern [expert only]:
              - Pattern to rewrite the call of the c++ constructor.
              - It is a string, argument name and defining a result of the c_type
                e.g., the default pattern is ::
                auto result = c_type (a,b,c)
        - build_from_regular_type_if_view : boolean.
              - If True, and the type is a view, the wrapper calls the C++ constructor *of the corresponding regular type*.
              - If False, it simply calls the constructor the C++ type.
              - This allows to construct object which are wrapped by view (like gf e.g.), by calling the
                constructor of the regular type, much simpler, than the view.
        - python_precall :
            - A string of the type "module.function_name"
              where function_name is a python function to be called before the call of the C++ function.
            - It must take  F(*args, **kw) and return (args, kw)
        - python_postcall :
            - A string of the type "module.function_name"
              where function_name is a python function to be called after the call of the C++ function.
            - The function must take a python object, and return one...
        - doc : the doc string.
        """
        f = cfunction(signature, calling_pattern = calling_pattern, is_constructor = True, is_method = True,  doc = doc)
        all_args = ",".join([ ('*' if t in module_._wrapped_types else '') + n  for t,n,d in f.args])
        f._calling_pattern = ''
        if calling_pattern is not None :
          f._calling_pattern, all_args = calling_pattern + '\n', "std::move(result)"
        if self.c_type_is_view and build_from_regular_type_if_view :
          f._calling_pattern += "((%s *)self)->_c = new %s(%s (%s));"%(self.py_type, self.c_type,_regular_type_if_view_else_type(self.c_type),all_args)
        else :
          f._calling_pattern += "((%s *)self)->_c = new %s (%s);"%(self.py_type, self.c_type,all_args)

        if not self.constructor :
            self.constructor =  pyfunction(name = "__init__", is_method = True, doc = doc, python_precall = python_precall, python_postcall = python_postcall)
            self.constructor.is_constructor = True
        self.constructor.overloads.append(f)

    def add_method(self, signature, name =None, calling_pattern = None, no_self_c = False, is_method = False,  is_static = False,
                  python_precall = None, python_postcall = None, doc = '', release_GIL_and_enable_signal = False, c_name = None):
        """
        Add a C++ overload to a method of name name.

        - signature : signature of the function, with types, parameter names and defaut value
             rtype( arg1 name1, arg2 name2 = default2, ....)
             signature can be :
                - a string of 2 possible forms (i.e. c_name can be omitted) :
                    - rtype (arg1 name1, arg2 name2 = default2, ....)
                    - rtype c_name ( arg1 name1, arg2 name2 = default2, ....)
                - a dict : rtype -> string , args -> list of tuples [ (c_type, variable_name, default_value)]
                - rtype : the C++ type returned by the function. None for constructor
             default_value is None when there is no default.
        - name : name given in Python
                 If None, the C++ name extracted from the signature is used.
        - calling_pattern :
            - Pattern to rewrite the call of the c++ function,
            - It is a string, using self_c, argument name and defining result at the end if rtype != void
              e.g., the default pattern is :
              auto result = self_c.method_name(a,b,c).
            - If None, the signature must contain c_name
        - no_self_c : boolean. do not generate self_c reference in C++ code, in
                      some rare calling_pattern. Avoid a compiler warning.
        - is_method : boolean
        - is_static : boolean. Is is a static method
        - python_precall :
            - A string of the type "module.function_name"
              where function_name is a python function to be called before the call of the C++ function.
            - It must take  F(*args, **kw) and return (args, kw)
        - python_postcall :
            - A string of the type "module.function_name"
              where function_name is a python function to be called after the call of the C++ function.
            - The function must take a python object, and return one...
        - doc : the doc string.
        - release_GIL_and_enable_signal [expert only] :
           - For long functions in pure C++.
           - If True, the GIL is released in the call of the C++ function and restored after the call.
           - It also saves the signal handler of python and restores it after the call,
             and enables the C++ triqs signal_handler.
           - This allows e.g. to intercept Ctrl-C during the long C++ function.
           - **Requirement** :
              The function wrapped must be pure C++, i.e.  no call whatsoever to the python C API, directly or indirectly.
              otherwise the behaviour is undefined.
       """
        f = cfunction(signature, calling_pattern = calling_pattern, no_self_c = no_self_c, is_constructor = False,
             is_method = True,  is_static = is_static, release_GIL_and_enable_signal = release_GIL_and_enable_signal, doc = doc, c_name = c_name or name)
        name = name or f.c_name
        if name not in self.methods :
            self.methods[name] = pyfunction(name = name, is_method = True, is_static = is_static, doc = doc, python_precall = python_precall, python_postcall = python_postcall)
        self.methods[name].overloads.append(f)

    def add_call(self, **kw) :
        """
        Add the __call__ operator.

        It just call add_method, for the operator(), with name = "__call__"

        Cf add_method documentation.
        """
        if 'c_name' not in kw and 'calling_pattern' not in kw : kw['c_name']= "operator()"
        self.add_method(name = "__call__", **kw)

    class _iterator :
        def __init__(self,c_type, c_cast_type, begin, end) :
          self.c_type, self.c_cast_type, self.begin, self.end = c_type, c_cast_type, begin, end

    def add_iterator(self, c_type = "const_iterator", c_cast_type = None, begin = "std::begin", end = "std::end") :
        """
          Add an iterator, wrapping a C++ iterator.
          Parameters :
           - c_type : type of the C++ variable
           - c_cast_type : If not None, the result of the C++ iterator dereference if converted to the cast_type.
           - begin, end :
        """
        self.iterator = self._iterator(c_type, c_cast_type, begin, end)

    def add_pure_python_method(self, f, rename = None):
        """
        Add a method name (or an overload of method name).
        f can be :
           - a string module1.module2.fnt_name
           - a function in python
        """
        def process_doc(doc) :
            return doc.replace('\n','\\n') if doc else ''
        if type(f) ==type('') :
           module, name = f.rsplit('.',1)
           try :
               m = __import__(module.rsplit('.')[-1])
               doc = m.__dict__[name].__doc__
           except :
               raise
           self.pure_python_methods[rename or name] = pure_pyfunction_from_module(name = name, module = module), 'module', process_doc(doc)
        elif callable(f) :
           assert rename == None
           self.hidden_python_function[f.__name__] = f
           self.pure_python_methods[f.__name__] = f.__name__, 'inline', process_doc(f.__doc__)
        else : raise ValueError, "argument f must be callable or a string"

    class _member :
        def __init__(self, c_name, c_type, py_name, read_only, doc) :
          self.c_name, self.c_type, self.py_name, self.doc, self.read_only = c_name, c_type, py_name or c_name, doc, read_only

    def add_member(self, c_name, c_type, py_name = None, read_only = False, doc = ''):
        """
        Add a class member
        Parameters :
           - c_name : name of the variable in C++
           - c_type : type of the C++ variable
           - py_name : name of the variable in python. If None, use c_name.
           - read_only : bool
           - doc : the doc string.
        """
        self.members.append( self._member(c_name, c_type, py_name, read_only, doc))

    class _property :
        def __init__(self, name, getter, setter, doc) :
          self.name, self.getter, self.setter, self.doc = name, getter, setter, doc

    def add_property(self,  getter, setter = None, name = None, doc = ''):
        """
        Add a property
        Parameters :
         - getter : the cfunction representing the get part
         - setter : the cfunction representing the set part or None if the property if read only
         - name : name in python. If None, try to use the C++ name of the getter.
         - doc : the doc string.
        """
        if not isinstance(getter, str) : getter.is_method = True
        self.properties.append( self._property(name or getter.c_name, getter, setter, doc) )

    def add_len(self, c_name = None, calling_pattern = None, doc = "Length") :
        """
        Add the len operator
        """
        if not c_name and not calling_pattern : c_name = "size"
        self.add_method(name = "__len__impl", calling_pattern = calling_pattern, signature="int %s()"%c_name, doc= doc)
        self.methods['__len__impl'].do_implement = False # do not implement automatically, the signature is special

    def add_getitem(self, signature, calling_pattern = None, doc = "operator[]" ) :
        """
        Add a the __getitem__ operator
        """
        self.add_method(name = "__getitem__impl", calling_pattern = calling_pattern, doc = doc, signature = signature, c_name = "operator[]")

    def add_setitem(self, signature, calling_pattern = None, doc = "operator[]", **d ) :
        """
        Add a the __setitem__ operator
        """
        self.add_method(name = "__setitem__impl", calling_pattern = calling_pattern or "self_c[i] = v", doc = doc, signature = signature, **d)

    def add_method_copy(self) :
        """Add a method copy, that make a **deep** copy, using triqs::make_clone"""
        self.add_method(name = "copy", calling_pattern = self.c_type + " result = triqs::make_clone(self_c)", signature = self.c_type +"()", doc = "Make a copy (clone) of self")

    def add_method_copy_from(self) :
        """Add a copy_from, using C++ assignment"""
        # other by pointer, it is necessarly a wrapped type
        self.add_method(name = "copy_from", calling_pattern = " self_c = *other", signature = 'void(' + self.c_type +" other)", doc = "Assignment")

    def _prepare_for_generation(self) :
        """Internal :  Called just before the code generation"""
        self.has_mapping_protocol = '__getitem__impl' in self.methods or '__len__impl' in self.methods
        if '__setitem__impl' in self.methods and not  '__getitem__impl' in self.methods : raise RuntimeError, "Can not generate a class with a setter and no getter"

class module_ :
    """
       Representation of a module
    """
    _wrapped_types = []

    def __init__(self, full_name,  doc = '') :
        """
        - full_name = complete name of the module (after install, e.g.  pytriqs.gf.local.gf
        - doc : doc string
        """
        self.full_name = full_name
        self.name = full_name.rsplit('.',1)[-1]
        self.doc = doc
        self.classes = {}    # dict : string -> class_. Key is the Python type
        self.functions = {}  # functions : dict : string -> function_. Modules functions. Key is the python name.
        self.include_list = []
        self.enums = []
        self.using =[]
        self.python_functions = {}
        self.hidden_python_functions = {}
        self.module_path_list = []
        self._preamble = ''

    def add_class(self, cls):
        """
          Add a class into the module.
          It should not exist in the module already.
        """
        if cls.py_type in self.classes : raise IndexError, "The class %s already exists"%cls.py_type
        self.classes[cls.py_type] = cls
        self._wrapped_types += [cls.c_type, cls.c_type_absolute]  # we can call is by its name or its absolute name

    def add_function(self, signature, name =None, calling_pattern = None, python_precall = None, python_postcall = None, doc = '', release_GIL_and_enable_signal = False):
        """
        Add a C++ overload to function of the module

        - signature : signature of the function, with types, parameter names and defaut value
             rtype( arg1 name1, arg2 name2 = default2, ....)
             signature can be :
                - a string of 2 possible forms (i.e. c_name can be omitted) :
                    - rtype (arg1 name1, arg2 name2 = default2, ....)
                    - rtype c_name ( arg1 name1, arg2 name2 = default2, ....)
                - a dict : rtype -> string , args -> list of tuples [ (c_type, variable_name, default_value)]
                - rtype : the C++ type returned by the function. None for constructor
             default_value is None when there is no default.
        - name : name given in Python
                 If None, the C++ name extracted from the signature is used.
        - calling_pattern :
            - Pattern to rewrite the call of the c++ function,
            - It is a string, using self_c, argument name and defining result at the end if rtype != void
              e.g., the default pattern is :
              auto result = self_c.method_name(a,b,c).
            - If None, the signature must contain c_name
        - python_precall :
            - A string of the type "module.function_name"
              where function_name is a python function to be called before the call of the C++ function.
            - It must take  F(*args, **kw) and return (args, kw)
        - python_postcall :
            - A string of the type "module.function_name"
              where function_name is a python function to be called after the call of the C++ function.
            - The function must take a python object, and return one...
        - doc : the doc string.
        - release_GIL_and_enable_signal [expert only] :
           - For long functions in pure C++.
           - If True, the GIL is released in the call of the C++ function and restored after the call.
           - It also saves the signal handler of python and restores it after the call,
             and enables the C++ triqs signal_handler.
           - This allows e.g. to intercept Ctrl-C during the long C++ function.
           - **Requirement** :
              The function wrapped must be pure C++, i.e.  no call whatsoever to the python C API, directly or indirectly.
              otherwise the behaviour is undefined.
       """
        f = cfunction(signature, calling_pattern = calling_pattern, release_GIL_and_enable_signal = release_GIL_and_enable_signal, doc = doc,c_name = name)
        name = name or f.c_name
        if name not in self.functions :
            self.functions[name] = pyfunction(name = name, doc = doc, python_precall = python_precall, python_postcall = python_postcall)
        self.functions[name].overloads.append(f)

    def add_python_function(self, f, name = None, hidden = False) :
        assert callable(f)
        if not hidden :
            self.python_functions[name or f.__name__] = python_function(name or f.__name__, f)
        else :
            self.hidden_python_functions[name or f.__name__] = python_function(name or f.__name__, f)

    def add_include(self, *filenames) :
        """
        Add the filenames as C++ include in the generated wrapper and header.
        """
        self.include_list.extend(filenames)

    def add_using(self,ns) :
        """
        Add the using statement into the generated wrapper (and NOT the header).
        """
        self.using.append(ns)

    def add_preamble(self, preamble) :
        """
        Add the using statement into the generated wrapper (and NOT the header).
        """
        self._preamble += preamble + '\n'

    def use_module(self, modulename) :
        """
         From the name of the module :
           - add the header file generated for this module to the C++ include list
           - read this file, extract the list of _wrapped_types, and add it to the wrapped_type list.
        """
        f = None
        for path in module_path_list :
          hppfile = path + '/' +  modulename + '.hpp'
          if os.path.exists(hppfile) :
              f = open(hppfile ,'r')
              break
        if not f : raise RuntimeError, "Can not find the module %s.\n  ... module_path_list = %s"%(modulename, self.module_path_list)

        while f.readline().strip() != "// WrappedTypeList" :
            pass
        l = f.readline()[3:] # // strip "// "
        self._wrapped_types += eval(l)
        self.add_include(hppfile)
        #print "Loading triqs wrapped module %s"%modulename
        #print " ...  found C++ header file %s"%hppfile
        #print " ...  found wrapped types %s"%l

    class _enum :
        def __init__(self, c_name, values, c_namespace, doc) :
            self.c_name, self.c_namespace, self.values, self.doc = c_name, c_namespace + "::", values, doc
            self.c_name_absolute = self.c_namespace + self.c_name

    def add_enum(self, c_name, values, c_namespace ="", doc = '') :
        """
          Add an enum into the module.
          Parameters :
            - c_name : name in C++
            - c_namespace: namespace of the enum
            - values : list of string representing the C++ enum values
            - doc : the doc string.
        """
        self.enums.append( self._enum(c_name, values, c_namespace, doc))

    def _get_proper_converter(self, t) :
        if t in basic_types_formatting : return ''
        if t in self._wrapped_types : return ',converter_for_parser_wrapped_type<'+t+'>'
        if t.split('<',1)[0].endswith("_view") : return ',converter_for_parser_view_type<'+t+'>'
        return ',converter_for_parser_non_wrapped_type<'+t+'>'

    def _all_args_kw_functions(self) :
        l = [ (f, self.name, None) for f in self.functions.values()]
        for c in self.classes.values() :
            l += [(m,c.py_type, c.c_type) for m in c.methods.values() if m.do_implement]
            if c.constructor :
                l.append( (c.constructor,c.py_type, c.c_type))
        return l

    def _prepare_for_generation(self) :
        for c in self.classes.values() : c._prepare_for_generation()
        for n,f in class_.hidden_python_function.items() :
            self.add_python_function(f,name = n, hidden=True)

    def _generate_wrapper_code(self, mako_template, wrap_file) :
        self._prepare_for_generation()
        tpl = Template(filename=mako_template)
        rendered = tpl.render(module=self, regular_type_if_view_else_type= _regular_type_if_view_else_type, is_type_a_view = _is_type_a_view)
        with open(wrap_file,'w') as f:
           f.write(rendered)

    def _generate_py_converter_header(self, mako_template, wrap_file) :
        self._prepare_for_generation()
        tpl = Template(filename=mako_template)
        rendered = tpl.render(module=self)
        with open(wrap_file,'w') as f:
           f.write(rendered)

    def generate_code(self) :
        """
         Generate the wrapper and the header.
         The filenames are given in the sys.argv
        """
        self._generate_wrapper_code(mako_template = wrapper_mako, wrap_file = wrapper_target)
        self._generate_py_converter_header(mako_template = header_mako, wrap_file = header_target)